“I landed this job that, since I was 20 years old and trying to become an actor, I said I wanted. And aspects of it, don’t get me wrong, were wonderful,” the actress said. “But I knew by the end of the second season I couldn’t do that job anymore.”

Bush played Detective Erin Lindsay on the hit NBC show for four years, and had previously refused to discuss what made her leave the role beyond saying in an Instagram comment that “I left because I wanted to. End of story.” She said during the podcast that between Seasons 3 and 4 of the show, she sat down with her bosses to discuss her experience on the set.

“I said, ‘Here’s where we are. Here’s everything you’re aware of. Here’s how I’m coming to you today. If something really drastic doesn’t change, I’m leaving at the end of the year’ — because I understand how the business works and how women are treated — I said, ‘I’m giving you not two weeks notice and I’m not coming in here throwing s–t and breaking lamps and saying I’m never coming back. I’m giving you 23 episodes notice. I’m giving you that much time,” she recounted.

She added that she told them, “‘There will be no conversation in which I was hysterical, emotional, in which I was being a ‘irrational female’ or whatever you want to put on it. I’m literally sitting in front of you like cool as a cucumber. If this has to be like a big swinging d–k competition, I promise you I will win. But know this now: if we’re not having a very different conversation by Christmas, then you know with 100 percent certainty in December that come the end of April I’m leaving.’”

She described the experience as feeling “like I was trapped in a burning building… I was miserable and I had to go.” Universal TV, the studio behind “Chicago P.D.,” has not yet responded to Variety‘s request for comment. Bush’s character was written out by accepting a job offer with the FBI in New York City, taking her away from Chicago.

The actress, who has previously starred on “One Tree Hill” and was featured on “Chicago Fire,” “Med,” and “Justice,” recently made a talent and development deal with 20th Century Fox TV to star and produce in an upcoming pilot.